The invention relates to the area of sports such as skating, skiing and surfing and, more precisely, to xe2x80x9csnow surfingxe2x80x9d, generally referred to as snowboarding. More particularly, it relates to means intended to transmit the pressure exerted by the foot of the rider in the direction of the board, said means being designed to optimize the localization of the forces and the behavior of the board.
As is known, snowboard bindings are mounted on the snowboard with a certain freedom of rotation, making it possible to adjust the angle of the median longitudinal plane of the binding corresponding to that of the foot, relative to the longitudinal axis of the board.
To adopt the most ergonomic position possible, it may in fact be necessary for the front and back foot to have a particular orientation relative to the board.
The orientation of the front and back foot may differ and may likewise vary depending on the type of method employed. Thus, in the xe2x80x9cfree-stylexe2x80x9d method of snowboarding, the orientation of the feet and therefore of the binding is further from the longitudinal axis of the board than for the alpine method of snowboarding, in which the feet are closer to the longitudinal axis of the board.
Furthermore, there are two possible orientations for the foot relative to the perpendicular to the longitudinal axis of the board.
In fact, certain riders prefer to place their left foot toward the front of the board. Riders who adopt this method are referred to as xe2x80x9cregularxe2x80x9d.
Conversely, certain riders prefer to place their right foot toward the front of the board. Such riders are referred to as xe2x80x9cgoofyxe2x80x9d. As the back foot is generally more perpendicular to the longitudinal axis of the board than the front foot, it follows that the angle of the binding may vary greatly depending on whether it is used by a xe2x80x9cgoofyxe2x80x9d or xe2x80x9cregularxe2x80x9d rider.
Furthermore, it has been observed that the forces are generally exerted from the binding in the direction of the board and localized essentially in the end zones of the binding, corresponding to the front of the foot for xe2x80x9cfront sidexe2x80x9d curves and the back of the foot on xe2x80x9cback sidexe2x80x9d curves.
In other words, depending on the orientation of the binding relative to the board, the forces are exerted in an offset manner relative to the edges. The further the foot is from the perpendicular, the more the pressure is exerted in a zone remote from the edges and is thus less effective.
A first problem that the invention proposes to solve is that of optimizing the localization of the pressure exerted from the binding, whatever the orientation of the binding relative to the longitudinal axis of the board.
Furthermore, in the most frequent case where the binding is not perpendicular to the longitudinal axis of the board, the two zones of transmission of the pressure from the binding toward the board, which are situated at the front and back of the foot, are offset longitudinally relative to the board. It follows that the part of the binding situated between these two pressure zones has a rigidity which is added to and combined with the intrinsic rigidity of the board.
This combination has the effect of modifying the intrinsic mechanical strength characteristics of the board and takes it away from its theoretical behavior. Such a modification is prejudicial to the board""s resistance to the forces.
In particular, numerous cases have indeed been observed in which the board has broken in the end zones of the binding due to the occurrence of excessive stresses during bending of the board.
Another problem which the invention proposes to solve is that of loosening the binding relative to the board and reducing the influence of the mechanical rigidity of the binding on the intrinsic mechanical properties of the board.
It is therefore the object of the invention to allow optimization of the pressure exerted on the binding in the direction of the board while allowing a certain loosening of the rigidity of the binding and the board and at the same time retaining compatibility with the freedom of adjustment of the orientation of the binding relative to the longitudinal axis of the board in accordance with the different methods and different types of user.
The invention thus relates to an interface element used in snowboarding and intended to transmit the pressure exerted by the foot of the rider in the direction of the snowboard. Such an element has median longitudinal and transverse planes dividing the pressure zone into four quadrants.
This element is distinguished by the fact that two of the quadrants arranged diagonally have a rigidity greater than the two other quadrants so as to favor transmission of the pressure at the diagonal of the two quadrants of greater rigidity.
In other words, on a snowboard fitted with the characteristic interface element the pressure exerted by the user is not localized along the median longitudinal plane of the boot and of the binding but instead in a manner offset transversely.
The diagonal of the two quadrants of greater rigidity is advantageously oriented perpendicularly to the longitudinal axis of the board in such a way that the quadrants of greater rigidity are close to the edges, improving the precision with which the board can be guided.
In other words, in accordance with the invention the volume enclosed between the foot of the user and the upper face of the board has a rigidity which is distributed in such a way that the pressure is transmitted preferentially in a direction perpendicular to the longitudinal axis of the board.
Moreover, thanks to the characteristic interface element the mechanical influence of the area of pressure on the board is essentially limited to a reduced zone in the longitudinal direction of the board to the two quadrants of greater rigidity. In this way, the effect of the rigidity of the binding and of the members associated with it is relatively small during the bending of the board. The latter thus retains its intrinsic mechanical properties and its optimum behavior.
In practice, numerous embodiments make it possible to obtain a structure that favors pressure along the characteristic diagonal.
Thus, according to a first group of embodiments, the characteristic element can be formed by a spacer element placed between the binding and the upper face of the snowboard. This is then an interface plate intended to raise the binding. The rigidity of this spacer element varies over its area and is greater along a characteristic diagonal.
Thus, in a first variant, the spacer element can have two plugs of greater rigidity than the remainder of the element, which are incorporated into its structure in the two quadrants arranged diagonally.
In this way, when the binding is arranged on this spacer element, the forces exerted by the skier are essentially transmitted in the zones of greater rigidity, while the zones of lower rigidity deform and are compressed.
In another embodiment, the spacer element has at least two protruding parts intended to be embedded in complementary openings provided for this purpose in the seat of the binding.
In this way, the user""s boot is in contact with the spacer element in the two quadrants of greater rigidity, and the forces are thus transmitted directly via the protruding parts.
According to another embodiment, the seat of the binding can have protruding zones in the two quadrants of greater rigidity, these protruding zones making contact with the upper face of the board in two zones situated perpendicularly relative to the longitudinal axis of the board.
To take account of the different orientations corresponding to the xe2x80x9cgoofyxe2x80x9d and xe2x80x9cregularxe2x80x9d methods, the same characteristic interface element is suitable for use in accordance with the two different orientations of the foot relative to the board, by being turned around for example.
In another case under consideration allowing dual use, such an element has two series of four quadrants, each series being dedicated to one orientation of the foot relative to the board and having quadrants of greater rigidity on a diagonal different from the diagonal of greater rigidity of the other series, the two series having two quadrants in common.
In other words, such an element has six elementary zones intended to form quadrants, four of these zones being used in the xe2x80x9cregularxe2x80x9d position and the two other zones being used with two of the first in the xe2x80x9cgoofyxe2x80x9d method.
In another embodiment, the interface element can be incorporated directly into the sole of the user""s boot, in which case the sole of the boot has elements of greater rigidity arranged on a diagonal passing through the median longitudinal plane of the boot.